In general, vibrations are problematic when dealing with acoustical assemblies for hearing devices, including hearing aids. In particular, vibrations generated by the acoustical assembly itself, for example self-generated receiver vibrations, are a huge problem and should be dealt with in order to avoid acoustical feedback problems within the assembly.
One approach to reduce self-generated vibrations is suggested by the applicant in US 2012/0255805 A1. In this particular reference an arrangement for reducing vibrations in the x and z directions are proposed, cf. in particular FIGS. 5 and 6 of US 2012/0255805 A1.
The arrangement proposed US 2012/0255805 A1 applies two oppositely arranged, and spatially shifted, moving armature receivers. As addressed in for example paragraphs [0063] and [0064] vibrations in the x and z directions are reduced. However, the oppositely arranged forces in the x and z directions introduce an unintended torque in the y direction around the centre of mass of the arrangements shown in FIGS. 5 and 6.
It may be seen as an object of embodiment of the present invention to provide a vibro acoustical assembly where also torque induced vibrations are reduced.
It may be seen as a further embodiment of the present invention to provide a vibro acoustical assembly where a plurality of receivers are arranged in a manner that creates space for an inclusion of one or more microphone units.